1. Technical Field
The present invention relates to a power supply employing pulse-width modulation and a digital-to-analog converter, a power supply control device, and a manufacturing method of the power supply.
2. Related Art
An image formation device for forming an image on a print medium (e.g. paper) uses electric power of various voltages for various processes (steps) such as exposure, development, image transfer and fixation. Such a variety of electric power is supplied from a high-voltage power supply to the various processes stably as analog outputs controlled according to analog control signals. Each analog control signal can be generated by means of pulse-width modulation (PWM) or a digital-to-analog converter according to a digital control signal which is supplied from a control circuit board having a CPU.
However, there has been conducted no detailed examination on how to properly control multiple channels of electric power by selectively and appropriately using such various types of analog control signal generating methods. This kind of problem is not restricted to image formation devices but is a general problem common to electric power control for controlling the supply of multiple channels of electric power.